Science Behind Acupuncture

Andrew Dainsberg, DVM, CVA

How does acupuncture work? We know that it does work from thousands of years of experience. Yin and yang and traditional Chinese medical theory can explain it. But what about some "science?" Researchers have conducted scientific double blind studies to prove that it is not a placebo or hypnosis. Recently, researchers at the University of Medicine and Dentistry of New Jersey used functional magnetic resonance imaging (fMRI) to prove that acupuncture decreased certain brain activity in human volunteers experiencing pain. The decreased brain waves corresponded to lowered pain perception in the volunteers. Huey-Jen Lee, their chief neuroradiologist, stated "Western doctors have been reluctant to use acupuncture because they did not know why it was effective. Now we are learning more about the physical response created by acupuncture."

how does it work?

Acupoints are tiny areas on the skin that contain relatively concentrated levels of nerve endings, lymphatics, and blood vessels. Acupoints can be readily identified by their lower electrical resistance, and are usually located in small palpable depressions detectable by trained acupuncturists. Stimulation from placing acupuncture needles in acupoints initiates events that have been studied and grouped into three summarized Western theories that explain how acupuncture works.

1) Neurological: Pain perception is altered through acupuncture's effects on specific nerve fibers. The "gate theory" proposes that acupuncture at acupoints stimulates peripheral nerves which sequentially turn off specific nerve fibers in the central nervous system to effectively cease the transmission of pain impulses and modulate disease. This theory is probably responsible for some of the effects of acupuncture but on the basis of several studies, cannot stand alone to account for all of the known effects.

2) Neuroendocrine: Neurotransmitters such as beta-endorphin, met-enkephalin, serotonin, and Substance P modulate the effects of acupuncture, resulting in physiologic effects on the body. The key to this theory is the proposal that structures other than nerves are responsible for some of acupuncture's effects. Studies have shown that veins and cerebral spinal fluid carry neurotransmitters and hormones that mediate effects such as pain control. Increasing white blood cell levels is a known effect of acupuncture that probably involves both neuroendocrine transmitters and the nervous system.

3) Local Mediation: Due to the concentration of nerve endings, certain cells and vessels at acupoints, a relatively large integrated response is created when acupoints are needled. This response launches an elaborate cascade of enzymatic, chemical and vasoactive changes that play a role in the proven results of acupuncture.

In summary, it seems that there are structures involved in carrying the effects of acupuncture and that there are messages being delivered that promote health and pain relief. Acupuncture is truly an amazing medicine...